How many letters does the top answer for “make a strident sound” have?

The most common answer is blare (5 letters).

Crossword clue: make a strident sound

2 answers found in Letterora's clue database (Wikidata facts, Open Trivia DB, WordNet and Webster definitions — all licensed sources).

blare 5 letters wn-def

a loud harsh or strident noise

blast 5 letters wn-def

make a strident sound

make a buzzing sound 50% similar → bombinate, buzz

make a crackling sound 50% similar → crackle, crepitate

make a murmuring sound 50% similar → purl, sough

make a rattling sound 50% similar → brattle, clatter

make a rhythmic sound 50% similar → thrum